Advanced surgical simulation constructions and methods

ABSTRACT

A surgical simulation system is provided. The system includes at least one simulated body organ placed upon the base of an organ tray and at least one covering layer placed over the simulated body organ. At least one of the simulated body organ and covering layer includes electro-conductive gel that is operably severable under application of electrical current to simulate electrosurgery in a training environment. The training environment comprises a top cover connected to and spaced apart from a base to define an internal cavity that is partially obstructed from direct observation by a practitioner. The tray, simulated body organs and covering layer are placed inside the internal cavity for the practice of laparoscopic surgical procedures.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to and benefit of U.S. ProvisionalPatent Application Ser. No. 61/771,316 filed on Mar. 1, 2013 entitled“Advanced surgical simulation constructions and methods” which isincorporated herein by reference in its entirety.

FIELD OF THE INVENTION

This application is generally related to surgical training tools, and inparticular, to anatomical models simulating organs or tissue forteaching and practicing various surgical techniques and procedures.

BACKGROUND OF THE INVENTION

Medical students as well as experienced doctors learning new surgicaltechniques must undergo extensive training before they are qualified toperform surgery on human patients. The training must teach propertechniques employing various medical devices for cutting, penetrating,clamping, grasping, stapling and suturing a variety of tissue types. Therange of possibilities that a trainee may encounter is great. Forexample, different organs and patient anatomies and diseases arepresented. The thickness and consistency of the various tissue layerswill also vary from one part of the body to the next and from onepatient to another. Accordingly, the skills required of the techniquesand instruments will also vary. Furthermore, the trainee must practicetechniques in readily accessible open surgical locations and inlocations accessed laparoscopically.

Numerous teaching aids, trainers, simulators and model organs areavailable for one or more aspects of surgical training. However, thereis a need for model organs or simulated tissue elements that are likelyto be encountered in endoscopic, laparoscopic, transanal, minimallyinvasive or other surgical procedures that include the removal of tumorsor other tissue structures. For example, there is a need for realisticmodel organs for the repeatable practice of removing a tumor or otherundesired tissue followed by the closure of the target area by suturingor stapling as part of the same surgical procedure.

In view of the above, it is an object of this invention to provide asurgical training device that realistically simulates such particularcircumstances encountered during surgery. The medical training andsimulation systems and devices of the present invention provide a userwith visual, tactile and technical properties that emulate thesituations extant in live surgical procedures. Emulation is an effort toequal or surpass real surgical conditions or effects in a surgicalsimulation.

In order to simplify training and minimize the use of cadavers insurgical training and in practice, the present invention contemplatesthe use of synthetic materials that are compounded, configured andcombined to emulate the properties, responses and characteristics ofhuman or animal tissue under surgical conditions and in response to theactivities of surgical instruments. Such conditions and activities mayinclude incision, penetration, dissection, occlusion, anastomosis,approximation, ablation, and the like.

Many surgical procedures involve the use of energy-based surgicalinstruments such as electrosurgical blades, probes, scissors, graspers,dissectors and the like. Electrosurgery is generally considered theapplication of high voltage, high frequency electrical energy to tissuefor the purpose of cutting or destroying. Electrocautery is a type ofelectrosurgery in which an electrical current generates resistanceheating in the instrument, which is sufficiently high to apply to tissuefor the purpose of cutting or destroying tissue. Additionally, manyprocedures make use of energy devices based on high frequency sound.These instruments provide a surgeon with the convenience of nearlyeffortless cutting and dissection and nearly instant thermal hemostasis.Such instruments have become a standard within the surgical communityand are used regularly.

It becomes readily apparent that any fake organs or organ simulationmodules or training modules must include the ability to train in the useof energy-based surgical instruments. Many of the existing training orsimulation modules require the use of harvested animal tissue, syntheticmaterials that must be wetted or infused with saline solution ormaterials having embedded metallic particles so that they areelectrically conductive and suitable for energy-based surgical techniquetraining. The most preferred synthetic materials such as siliconerubber, latex, vinyl, polyester, polyurethane and the like do notrespond to energy-based surgical instruments and devices in a way thatsatisfies the need to train users to use the instruments in an actualsurgical procedure. Therefore, one aspect of the present invention is toprovide a combination of synthetic materials, some that have dielectriccharacteristics, and some that are electrically conductive and yet mimicthe physical properties of natural tissue and action of energy-basedsurgical instruments and devices. In addition, the present inventionprovides a method for constructing various body parts, conduits, organs,cysts, tumors and the like that provides life-like synthetic samples.

SUMMARY OF THE INVENTION

According to one aspect of the invention a surgical simulation system isprovided. The surgical simulation system includes a tray having a basewith a perimeter and one or more anatomical receptacle portion formed byat least one upstanding wall configured to substantially cooperate andconform in size and shape with one or more simulated body organ locatedwithin the one or more receptacle portion. The system includes one ormore simulated body organ placed upon the base within the one or morereceptacle portion. At least one covering layer is placed over the oneor more simulated body organ. The covering layer is attached to the oneor more simulated body organ in at least one location. The least one ofthe one or more simulated body organ and covering layer includeselectro-conductive gel operably severable under application ofelectrical current to simulate electrosurgery in a training environment.

According to another aspect of the invention, a surgical simulationsystem for the practice of electrosurgical activity is provided. Thesurgical simulation system includes a simulated tissue structure thatincludes an inner layer that is adjacent to and in contact with an outerlayer. The inner layer comprises a foam material and the outer layercomprises an elastomeric hydrogel. The inner layer defines an interiorcavity and both the inner layer and the outer layer define a shape of atleast a portion of a uterus. The surgical simulation system alsoincludes a simulated pathology located adjacent to or embedded in theinner layer. The simulated pathology is removable from the simulatedtissue structure. The elastomeric hydrogel is electro-conductive suchthat it is operably severable under application of electrical current tosimulate electrosurgery in a training environment.

According to another aspect of the invention, a method for surgicalsimulation is provided. The method includes the step of providing anorgan tray having a base with one or more simulated body organ on it. Acovering layer is placed over the one or more simulated body organ. Thecovering layer includes a first planar layer of non-conductive materialand a second planar layer of electro-conductive gel. The covering layeris placed over the one or more simulated body organ such that the secondlayer is adjacent to the one or more simulated body organ. The organtray is placed into an internal cavity of a surgical training devicesuch that the organ tray is at least partially obstructed from directvisual observation by a practitioner. The surgical training deviceincludes a top cover spaced apart from the base. The internal cavity isdefined between the top cover and base. The surgical training deviceincludes an aperture or penetrable simulated tissue region in the topcover. The method further includes the step of inserting a scopeconfigured to capture video of the internal cavity through the apertureor penetrable simulated tissue region and into the internal cavity ofthe training device. At least one instrument is inserted through theaperture or penetrable simulated tissue region into the internal cavityof the training device. The method includes the step of separating thefirst layer from the second layer with the at least one instrument.

According to one aspect of the invention, a method of making a simulatedtumor is provided. The tumor is made by mixing uncured silicone rubberwith untreated fumed silicon dioxide. The mixture is then shaped andcured to form a simulated tumor.

According to one aspect of the invention, a simulated tissue structurefor surgical training is provided. The structure includes an organ tray,simulated organs placed on the tray and a covering layer. The coveringlayer includes a semi-transparent sheet of silicone rubber.

According to one aspect of the invention, a simulated tissue structurefor surgical training is provided. The structure includes an organ tray,simulated organs placed on the tray and a covering layer. The coveringlayer includes a semi-transparent sheet of silicone rubber and asemi-transparent sheet of hydrogel material.

According to one aspect of the invention, a method for forming acovering layer for a tray containing simulated tissue includes the stepof mixing electro-conductive material such as platinum or tin intoliquid silicone. The mixture is spread onto a first layer ofpolyethylene foam. A second layer of polyethylene foam is placed overthe silicone layer. A textured roller or stamping device is moved overthe surface of the second layer of foam to calendar the siliconematerial between the foam layers of foam. The silicone layer is removedfrom between the foam layers.

According to another aspect of the invention, a simulated organ model ofa uterus is provided. The model includes an outer shell of soft siliconeand an inner layer of foam with simulated tumors located between theouter shell and inner layer.

According to another aspect of the invention, a simulated organ model ofa uterus is provided. The model includes an outer shell of soft siliconeand an inner layer of foam with simulated tumors located inside theinner foam layer.

According to another aspect of the invention, a simulated organ model ofa uterus is provided. The model includes fallopian tubes of siliconecontaining electro-conductive material. The fallopian tube includes alumen extending between a first end and a second end and a bulbousportion near the second end that transitions to a funnel shape at thesecond end having a plurality of axial cuts in the funnel portion. Atleast a portion of the lumen includes a soft fibrous material.

According to another aspect of the invention, a simulated organ model ofa uterus is provided. The model includes fallopian tubes of siliconecontaining electro-conductive material. The fallopian tube includes alumen extending between a first end and a second end and a bulbousportion near the second end that transitions to a funnel shaped at thesecond end having a plurality of axial cuts in the funnel portion. Atleast a portion of the lumen includes a soft fibrous material and asimulated ectopic pregnancy is placed inside the bulbous portion. Thesimulated ectopic pregnancy is made of silicone rubber and untreatedfumed silicon dioxide.

According to another aspect of the invention, a simulated organ model ofa stomach is provided. The model includes a hollow stomach-shapedbladder having a proximal opening and a distal opening. The modelincludes a predetermined pathway for practicing resection of at least aportion of the stomach along the predetermined pathway. Thepredetermined pathway is defined by a portion of two opposing innersurfaces of the stomach model being joined together.

According to another aspect of the invention, a tray for receiving modelorgans is provided. The tray includes a bottom surface and at least onereceptacle portion for receiving at least one organ. The at least onereceptacle portion is formed by upstanding walls having a height andshape that substantially conforms to the height, shape and size of theorgan to be placed into the receptacle portion.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a side view of a surgical training device with amodel organ according to the present invention.

FIG. 2A illustrates a side cross-sectional view of a simulated tissuestructure according to the present invention.

FIG. 2B illustrates a side cross-sectional view of a simulated tissuestructure with tumor excised according to the present invention.

FIG. 2C illustrates a side cross-sectional view of a simulated tissuestructure with an open suture according to the present invention.

FIG. 2D illustrates a side cross-sectional view of a simulated tissuestructure with a closed suture according to the present invention.

FIG. 3A illustrates a top view of a defect layer having a circularshaped defect according to the present invention.

FIG. 3B illustrates a top view of a defect layer having an elongateddefect according to the present invention.

FIG. 3C illustrates a top view of a defect layer having an amorphousdefect according to the present invention.

FIG. 3D illustrates a top view of a defect layer having a two-piecedefect according to the present invention.

FIG. 3E illustrates a top view of a multi-part defect layer according tothe present invention.

FIG. 3F illustrates a top view of a defect layer having multiple defectsaccording to the present invention.

FIG. 4 illustrates a top view of a simulated tissue structure accordingto the present invention.

FIG. 5 illustrates a side cross-sectional view of a simulated tissuestructure according to the present invention.

FIG. 6A illustrates a perspective view of a modular tissue structure andsupport according to the present invention.

FIG. 6B illustrates a perspective view of a modular tissue structure andsupport according to the present invention.

FIG. 7 illustrates a cross-sectional view of a simulated tissuestructure configured to mimic a human uterus according to the presentinvention.

FIG. 8 illustrates a top view of a modular tissue structure according tothe present invention.

FIG. 9 illustrates a side view of a modular tissue structure accordingto the present invention.

FIG. 10A illustrates a perspective view of a simulated tissue structureaccording to the present invention.

FIG. 10B illustrates a perspective view of a simulated tissue structureaccording to the present invention.

FIG. 11A illustrates a perspective view of a simulated tissue structureaccording to the present invention.

FIG. 11B illustrates a perspective view of a simulated tissue structureaccording to the present invention.

FIG. 12 illustrates a perspective view of a suture needle and asimulated tissue structure according to the present invention.

FIG. 13 illustrates a schematic of a model of female uterine anatomywith tumor placement according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

A surgical training device 10 that is configured to mimic the torso of apatient such as the abdominal region is shown in FIG. 1. The surgicaltraining device 10 provides a simulated body cavity 18 substantiallyobscured from the user for receiving model organs or simulated or livetissue 20. The body cavity 18 is accessed via a tissue simulation region19 that is penetrated by the user employing devices to practice surgicaltechniques on the tissue or organ 20 found located in the body cavity18. Although the body cavity 18 is shown to be accessible through atissue simulation region 19, a hand-assisted access device orsingle-site port device may be alternatively employed to access the bodycavity 18 as described in U.S. patent application Ser. No. 13/248,449entitled “Portable Laparoscopic Trainer” filed on Sep. 29, 2011 andincorporated herein by reference in its entirety. The surgical trainingdevice 10 is particularly well suited for practicing laparoscopic orother minimally invasive surgical procedures.

The surgical training device 10 includes a base 12 and a top cover 14connected to and spaced apart from the base 12 to define an internalbody cavity 18 between the top cover 14 and the base 12. At least oneleg 16 interconnects and spaces apart the top cover 14 and base 12. Amodel organ or simulated tissue 20 is disposed within the body cavity18. The model organ 20 shown in FIG. 1 is a partial colon or intestinethat is shown suspended from the top cover 14 by tethers 22 andconnected to at least one leg 24. The at least one leg 24 has anaperture (not shown) facing the internal body cavity 18. The model colon20 includes a tube 26 having a proximal end and a distal end. Theproximal end of the tube 26 is interconnected with the aperture of theleg 24 such that the aperture provides an access port to the lumen ofthe tube 26. The access port and aperture is shown to be closed off inFIG. 1 with an access device 28 which in combination with a sealeddistal end of the tube 26 provides a model organ 20 that is adapted forinsufflation with fluid deliverable via an insufflation port 30. Anoptional insert 32 made of soft material such as silicone creates arealistic interface for the access port. The distal end of the tube 26extends into the body cavity 18 and is suspended within the body cavity18. The interior of the tube 26 of the simulated organ 20 is accessiblevia the access port of leg 24 or via the tissue simulation region 19 orinstrument insertion ports 34. An endoscopic camera inserted into thebody cavity 18 or into the organ 20 via the access port generates a liveimage for display on a fold out video screen 36 shown in the closedposition in FIG. 1. An endoscope is a visualization device that is usedto view a hollow structure. Although the simulated organ 20 of FIG. 1 isideal for practicing procedures related to transanal minimally invasivesurgery, any simulated organ or tissue portion may be employed. Oneparticular aspect of the organ 20 is at least one tumor or defect 38 isprovided and connected to the organ. As shown in FIG. 1, the tumor 38 isconnected to the wall of the organ tube 26.

Turning now to FIG. 2A there is shown a partial side cross-sectionalview of a portion of a simulated organ 20 that includes the tumor 38.The simulated organ or tissue 20 includes a base layer or organ wall 40.The organ wall 40 is made from a material configured to mimic real livetissue such as silicone or other polymer and is dyed appropriately. Oneor more base layers 40 of varying thicknesses and colorations may beemployed to comprise the entirety of the wall 40. In one variation, theorgan wall 40 is rigid and made of polymeric material. Above the baselayer 40 is a second layer or defect layer 42. The defect layer 42 isthe same size or smaller than the base layer 40 forming a raisedplatform for the tumor 38. The defect layer 42 is connected to the baselayer 40 by adhesive or other means known to one having ordinary skillin the art including being integrally formed with the base layer 40 as asingle unit. The defect layer 42 is made of silicone and in onevariation of the same color as the base layer 40 such that the defectlayer 42 blends into the background of the base layer 40. The defectlayer 42 includes at least one defect or gap 44. In one variation, thedefect 44 is a pre-fabricated breach in the defect layer 42 that mimicsan incision, gap or other void in real tissue resulting from a tear,cut, removal or other surgical procedure that requires surgicalattention by way of suturing, stapling or the like to close the defect.Such a situation arises most often in the removal of a tumor 38 wheresurrounding tissue is also removed together with the tumor 38 topreventatively ensure the entirety of the tumor is excised leavingbehind a remnant defect in the tissue. The defect 44 comprises twoopposed sides or surfaces defining a gap therebetween. Although theadjacent sides or surfaces are shown to be vertical with respect to thebase layer 40, the invention is not so limited and the juxtaposedsurfaces or sides can have any shape and, for example, be curved. Thedefect 44 can be any shape as will be discussed with respect to FIGS.3A-3F.

Turning now to FIG. 3A, there is shown a top view of a defect layer 42having a circular defect 44. A defect layer 42 with an elongated, oblongor elliptically shaped defect 44 is shown in the FIG. 3B. The defect 44can be amorphic or any shape as shown in FIG. 3C. The defect layer 42may be multi-part as shown in FIG. 3D wherein the defect layer 42includes two or more adjacent defect layer pieces 42 a, 42 b juxtaposedto create at least one defect 44 therebetween. Another multi-part defectlayer 42 is shown in FIG. 3E where a plurality of adjacent defect layerpieces 42 a, 42 b and 42 c form one or more defects 44 therebetween. Ofcourse, a defect layer 42 may include multiple defects 44 a, 44 b and 44c as shown in FIG. 3F. The defects 44 may all be the same or havedifferent shapes as shown in FIG. 3F. The shape, thickness and size ofthe defect allow the surgeon trainee to practice suturing across defectsof varying difficulty. In one variation, the defect layer 42 is not ofequal thickness. Instead, the thickness of the defect layer 42 varies atthe defect 44 location to increase the difficulty of suturing or closingthe defect.

Referring back to FIG. 2A, a tumor 38 is located above the defect layer42. The tumor 38 is preferably a different color from the base layer 40or defect layer 42 or both such that it is readily identifiable by thetrainee. Preferably, the tumor 38 is made of silicone or other polymermaterial and is red, black, blue or dark brown in color. In general, thetumor 38 is of a darker color than the base or defect layers 40, 42 orotherwise in contrast therewith when viewed through a scope. In onevariation, the tumor 38 is connected to the defect layer 42 by adhesiveor other means known to one of ordinary skill in the art. In anothervariation, the tumor 38 is not connected or attached to the defect layer42 but is removably located thereon.

Still referencing FIG. 2A, the simulated tissue structure 20 includes acover layer 46 located above the tumor 38. In one variation, the coverlayer 46 overlays the tumor 38, defect layer 42 and the base layer 40.The cover layer 46 is preferably transparent or translucent in color andmade of a polymer material such as silicone. In another variation, thecover layer 46 is the same color as the base layer 40 or defect layer42. The cover layer 46 is at least as thick as the base layer 40 ordefect layer 42 and in one variation is thinner than the defect layer 42and in another variation is thinner than the base layer 40. The coverlayer 46 is sized to cover the entire tumor 38 and defect layer 42 andis big enough to contact the base layer 40 in one variation. In anothervariation, the cover layer 46 is sized to cover the entire tumor 38 andcontact the defect layer 40. The cover layer 46 is connected to the baselayer 40, defect layer 42, tumor 38 or any more than one of the threelayers by way of adhesive or other means known to one of ordinary skillin the art. In another variation, the cover layer 46 is smaller andconnected to the defect layer 42 alone. In yet another variation, thecover layer 46 is connected to both the defect layer 42 and base layer42 by adhesive or other means known to one of ordinary skill in the art.The cover layer 46 can be any shape or size and be configured to providea smooth surface to the surgeon instead of a layered surface to theartificial tumor location. The cover layer 46, tumor 38, defect layer 42or base layer 40 includes surface texturing in one variation. Also, thecover layer 46 assists in keeping the tumor 38 and defect layer 42sandwiched between the cover layer 46 and base layer 40 which isadvantageous in a variation wherein the tumor 38 is not adhered to thedefect layer 42. A top planar view of the base layer 40, defect layer42, cover layer 46 and tumor 38 is shown in FIG. 4. In one variation,any one or more of the base layer 40, defect layer 42 and cover layer 46is formed of silicone molded over a woven, fabric, or mesh material suchas nylon or cheesecloth so that the silicone layer has an integratedmesh structural support or other type of reinforcement. Any one or moreof the layers 38, 40, 42, 46 can include a fabric or mesh reinforcementcombined with an elastic polymer such silicone. The mesh support aids inpreventing the suture, staple, or suture needle from tearing through atleast one of layers and especially the defect layer 42 when the sutureis pulled to close the gap 44.

In FIG. 2B, the tumor 38 and a portion of the cover layer 46 are shownexcised from the base layer 40. The excision is performed by the traineeusing a surgical instrument such as a scalpel or other medicalinstrument to remove the tumor 38. The trainee will cut through thecover layer 46 around the tumor 38, isolate the tumor 38, lift andremove the tumor 38 away from the site to expose the underlying defect44 as shown in FIG. 2B. Then, as shown in FIG. 2C the trainee suturesthe defect 44 using a surgical suture 48 bringing the lips or edges ofthe defect layer 42 together as shown in FIG. 2D, thereby, practicingthe closing of a gap or wound created by the surgical removal of a tumor38. Cutting the at least one layer to create an opening and removing theartificial tumor and suturing the gap is performed while the simulatedtissue structure is disposed inside a simulated body cavity 18 of asurgical training device such that the simulated tissue structure is atleast partially obscured from view by the user.

Turning now to FIG. 5, there is shown another variation in which thereis no pre-formed gap or defect in the second or defect layer 42.Instead, upon excising the tumor 38, the defect is created by the userin one or more of the cover layer 46, defect layer 42, base layer 40 andany remaining tumor portion not removed by the user. The user would thenpractice suturing the created defect in any of these layers 38, 40, 42,46. In one such variation, one of the defect layer 42 or base layer 40is omitted from the construct. In another variation, the tumor 38 islocated on a base layer 40 and the defect layer 42 is placed over thetumor 38 such that the defect layer 42 is above the tumor 38. In such avariation, a cover layer 46 may or may not be included. If a cover layer46 is included it may be integrally formed together with the defectlayer as a separate unitary layer. In any of the constructs describedabove with respect to FIGS. 2-5, the constructs may be flipped upsidedown or otherwise the layers placed in reverse or otherwise theconstruct being approachable by the user from either the top or bottomdirection with the thicknesses and colors of the layers being adjustedaccordingly if necessary to provide the simulated effects of realtissue.

Turning now to FIGS. 6A and 6B, in any of the variations in thisdescription, the simulated tissue construct can be modular such that itis not integrally formed with the entire simulated organ 20 but insteadconfigured as a module 50 that is removable and interchangeable. One ormore modules 50 are supported or contained in a module support 52. Amodule support 52 includes a first surface 51, a second surface 53 andone or more tumor module receiving portions 54, 56, 58 formed in thesupport 52. The tumor support 52 can be rigid or pliable and made ofpolymeric material. The tumor support 52 may also comprise a sheet ofelastomeric material. The module receiving portions 54, 56, 58 are eachsized and configured to receive a correspondingly sized and configuredmodule 50. The modules 50 and module receiving portions 54, 56, 58 inFIG. 6 are shown to be circular; however, the tumor module 50 can be anyshape with a complementary shaped receiving portion formed in the modulesupport 52. The thickness of the support 52 can vary providing theconstruct with varying depths of tumor module 50 positioning. The modulereceiving portions 54, 56, 58 may include bottom walls onto which thetumor modules 50 may rest. Alternatively, the tumor receiving portions54, 56, 58 extend between openings in the first surface 51 and thesecond surface 53 with the modules 50 with tumor 38 being connectedbetween or at one of the openings at either surface 51, 53 or suspendedwithin the tumor receiving portion. In one variation, a single tumormodule 50 includes one or more tumors 38. The module support 52 isloaded with one or more tumor modules 50 and the simulated tissueconstruct 20 is inserted into the body cavity 18 of the surgicaltraining device 10, framework or other torso model. It can be placed onthe base 12 of the training device 10 or suspended within the bodycavity 18 of the training device 10. The simulated tissue construct 20and/or training device is fashioned with attachment mechanisms such asclips, fasteners, wires, hook-and-loop type fasteners and the like forplacement, suspension or connection of the simulated tissue construct 20to a training device 10.

With particular reference to FIG. 6B, there is shown a module support 52that includes more than one layer. The module support 52 of FIG. 6Bincludes a first layer 57 connected to a second layer 55. In onevariation, the first layer 57 is made of a sheet of elastomeric materialand the second layer 55 is made of any suitable polymeric material suchas low-density elastomeric foam. The second layer 55 serves as a supportfor the first layer 57. The second layer 55 also advantageously providesdepth to the module support 52 permitting the tumors 38 within themodules 50 to be placed deeply into the module support 52 relative tothe first surface 51. Module receiving portions 54, 56, 58 are formed inone or more than one of the first layer 57 and the second layer 55.Module receiving portions 54, 56, 58 formed in the second layer 55 mayhave a different shape than the shape the same module receiving portion54, 56, 58 has in the first layer 57. In one variation, the tumor module50 comprises at least only the simulated tumor 38 which is embedded orburied inside the second layer 55 with at least one of the first layer57 or second layer 55 constituting a defect layer which the user canpractice closing. As an alternative, the first layer 57 does not includea module receiving portion but instead the first layer 57 serves as acover layer which the user practices cutting through to access the tumor38 located in a tumor receiving portion formed in the second layer 55.In such variation, the first layer 57 can be a sheet of elastomericmaterial such as silicone and the second layer 55 is a layer oflow-density elastomeric foam. The module support 52 is planar as shownin FIGS. 6A and 6B or, alternatively, shaped to mimic a portion of thehuman anatomy, tissue or organ.

For example, FIG. 7 illustrates a support 52 that is shaped to mimic ahuman uterus. The support 52 includes a first layer 57 connected to asecond layer 55. In one variation, the first layer 57 is made of anysuitable polymeric material such as a sheet of elastomeric material andthe second layer 55 is made of any suitable polymeric material such aslow-density elastomeric foam. The second layer 55 serves as a supportfor the first layer 57 and advantageously permits the tumors 38 withinthe modules 50 or the tumors 38 by themselves to be connected to thesupport 52 and realistically extend deeply into the support 52 and bedispersed throughout the support 52 in various locations andorientations including being embedded into the first layer 57 as shownin FIG. 7. Tumor or module receiving portions 61 are formed in at leastone of the first layer 57 and second layer 55. The tumor receivingportions 61 may be pockets that are preformed in the second layer 55 orcan be formed by the user by cutting slits into the second layer 55. Inone variation, the tumors 38 are configured to mimic fibroid tumorscommonly found in the human uterus. Examples of fibroid tumors that aresimulated by the tumors 38 disposed in the support include but are notlimited to one or more of the following types of fibroids: pedunculatedsubmucosal fibroids, subserosal fibroids, submucosal fibroids,pedunculated subserosal fibroids and intramural fibroids. The user canapproach the support 52 to excise the simulated tumors 38 from the firstsurface 51 or the second surface 53 via the access channel or opening63. In one variation, the opening 63 serves as the only opening to thehollow portion 59 or alternatively the support 52 can have asubstantially C-shaped planar configuration with access available to theuser from above or below the planar C-shaped structure.

In one variation, the module support 52 in any of the variations is notplanar but is provided with a landscape that includes curves and otherstructures, mountains and valleys and various textures. The varyinglandscape provides the user with various levels of difficulty inapproaching each tumor location requiring the user to navigate aroundartifacts and features that may obscure the tumor location. Thesestructural artifacts in the tumor support 52 may be integrally formedwith the tumor support 52 or also be modular in structure similar to thetumor modules 50 making the anatomy landscape modules removable andinterchangeable. Tumor modules 50 are interchangeable with non-tumormodules that include, for example, features and artifacts or texturesmade of silicone or other material extending outwardly or inwardly fromthe one or more of the upper and lower surfaces 51, 53 of the modulesupport 52. The features in such non-tumor modules can have variousshapes to mimic anatomy that includes adjacent organ structures ortissues. For example, a non-tumor module can include a tubular form ofsilicone to mimic an intestine. The non-tumor and tumor modules 50 areremovably connected to the module support 52 by any means known to oneskilled in the art enabling the user to discard a module after use andthen to continue practicing by replacing the discarded module or movingto an adjacent module 50 in the module support 52 or changing out atumor module 50 for another tumor module 50 having a different featureor level of difficulty.

A variation of the tumor module 50 is shown in FIGS. 8 and 9. The tumormodule 50 includes a simulated tissue portion 60 connected to a support62. In the variation shown, the support 62 includes a top frame 64connected to a bottom frame 66. At least one of the top frame 64 andbottom frame 66 includes a window. The top frame 64 having a window 68is shown in FIG. 8. The bottom frame 66 may or may not include a window.If windows are provided in both the top frame 64 and the bottom frame66, the windows are aligned at least in part. The support 62 is sizedand configured to receive a simulated tissue portion 60 between the topframe 64 and the bottom frame 66. The top frame 64 is connectable to thebottom frame 66 to capture the unitary simulated tissue portion 60 or asimulated tissue portion 60 formed from multiple layers and, in onevariation, separable. In one variation, the frames 64, 66 are spacedapart from each other using spacers 70. Furthermore, at least one of thetop and bottom frames 64, 66 includes one or more connecting features 72configured to secure the tumor module 50 to a tumor support 52 (notshown). In FIG. 9, the connecting features 72 are shown as extendingpegs for insertion into corresponding holes formed in the tumor support52 to provide a snap-fit engagement. A friction fit or other fastenersor connecting means such as hook-and-loop type materials can be employedon the module 50 and module support 52 to connect the module 50 to thesupport 52 in a removable fashion.

Still referencing FIGS. 8 and 9, the simulated tissue portion 60 can beany of the constructs described above with reference to FIGS. 2-5. Withwindows formed in both the first and second frames 64, 66, the simulatedtissue portion 60 can be approached from either side of the module 50.Any layer described above as a cover layer may act as a top layer or asa bottom layer depending on from which side or direction the simulatedtissue portion 60 is approached. For example, a base layer may alsoserve as a top layer or as a bottom layer depending on which side ordirection the simulated tissue portion 60 is approached. In suchbi-directional constructs, the thicknesses and colors of the layers maybe adjusted accordingly to provide the desired simulated effect.

The simulated tissue portion 60 in FIG. 9 includes a first layer 74 anda second layer 76. The first and second layers 74, 76 are made from apolymeric material configured to mimic real live tissue such as siliconeor other polymer and can include dye of any one or more appropriatecolors or mesh, fabric, or other reinforcement. Each of the layers 74,76 includes a tumor-receiving portion 78, 80, respectively. Eachtumor-receiving portion 78, 80 is a concavity, indent, half-pocket or alocation of reduced layer thickness that is formed in the layers 74, 76.The tumor-receiving portions 78, 80 are substantially aligned to form apocket for the tumor 38. Although each layer 74, 76 in FIG. 9 is shownwith a tumor-receiving portion 78, 80, a single tumor-receiving portionis formed in at least one of the first and second layers 74, 76 in onevariation. A tumor 38 is disposed within the pocket formed by one ormore tumor-receiving portions 78, 80 formed in the one or more layers74, 76. The tumor 38 may be adhered to either layer 74, 76 orfree-floating inside the pocket. As shown in FIG. 9, the tumor-receivingportion formed in a layer can be considered to be one type of defect andthe variation of FIG. 9 describes a simulated tissue constructcomprising two defect layers with a tumor therebetween. As a userapproaches the simulated tissue portion 60, the user will see the targettumor location. Visualization of the target tumor 38 is enhanced by thetumor-receiving portion being thinner in thickness relative to the restof the layer with the thinning of the layer being provided by theconcavity or pocket. The user will then cut in the general location ofthe tumor cutting into at least one of the layers 74, 76 to remove thetumor 38. Cutting through one or more layers completes the creation of agap or full defect, which the user can then practice suturing orotherwise closing together. In another variation, there is notumor-receiving portion formed in the layers 74, 76. In such avariation, at least one tumor is disposed between the two layers 74, 76wherein the layers 74, 76 have a substantially uniform thickness withthe tumor 38 creating a minor bulge in the layers.

Turning now to FIGS. 10A, 10B, 11A, 11B and 12, there is shown anothervariation of a simulated tissue portion 86. The tissue portion 86 can beintegral or modular as described above. The tissue portion 86 includes abase layer 88 formed of any suitable polymeric material such as siliconeor other elastomeric polymer that may or may not include a reinforcementmaterial such as fabric, mesh, nylon or other reinforcement material orfiller that will resist tearing while carrying sutures or while beingsutured. The base layer 88 is connected to a defect layer 90 that isoverlaid onto the base layer 88. The defect layer 90 includes aplurality of protrusions extending upwardly from the base layer 88. Thedefect layer 90 may be integrally formed with the base layer 88 or be aseparate layer that is adhered to the base layer 88. As can be seen inFIGS. 10A, 11A and 12, the defect layer 90 is configured into a latticeshaped pattern such that the lattice is raised above the base layer 88or projects upwardly from the base layer 88. A lattice pattern isexemplary and any shape may be formed by the defect layer 90 such thatit contains a plurality of adjacent projections. These projections ofthe base layer 90 provide the user with locations to hook a sutureneedle into and as a platform to raise the tumor 38 a, 38 b above thebase layer 88 for easy excision. The tumors 38 a, 38 b may be adhered tothe defect layer 90 and a cover layer 92 may be included in onevariation. FIGS. 10A and 11A show the base layer 88, defect layer 90,tumors 38 a, 38 b and a cover layer 92 in a semi-exploded view of thesimulated tissue portion 86 wherein the cover layer 92 is raised abovethe other layers. The tumor 38 a of FIG. 10 a is substantially planarand is shown covered in FIG. 10B by the cover layer 92. Tumor 38 b ofFIG. 11A has greater height and is substantially spherical in shape andFIG. 11B shows the spherical tumor 38 b covered with the cover layer 92leaving a raised portion or protuberance in the construct. FIG. 12 showsthe tumor 38 being removed leaving a remnant defect 94 in the base layer88 and a suture needle crossing the gap in the defect 94 with the defecthaving been accessed under or through the cover layer 92.

Synthetic materials that mimic the characteristics of living tissue mayinclude silicone elastomers, natural latex, polyurethane elastomers,hydrogels and styrenic-block-copolymers. Generally, the elastomericmaterials are dielectric unless specially treated. An elastomer isgenerally any of various polymers with elastic properties resemblingthose of natural rubber. A hydrogel is generally a hydrophilic polymercontaining between 50% and 99% water. A thermoplastic generally pertainsto materials that may be repeatedly made soft and hard by heating andcooling. Thermoplastics are non-conductive and are suitable for makingthe tray or base, bone and other similar structures. A thermosetgenerally pertains to elastomeric materials that permanently harden orsolidify upon being heated or cured. Thermoset plastics arenon-conductive such as silicone and polyester and are suitable forforming pathologies, tumors and the like. Silicone elastomers areusually very soft, stable and non-conductive and therefore suitable forforming artificial organs such as the liver, kidney, spleen, ovaries,gallbladder, stomach, major arteries, colon, intestine, major veins,omentum, mesentery, pathologies and other anatomy. Natural latex is veryresilient and non-conductive and suitable for forming artificial muscle,cartilage and the like. Polyurethane elastomers and foams arenon-conductive and suitable for filling hollow structures, bone and thelike. Hydrogels SBCs may be conductive and are good for any softstructure to be operated upon by electrosurgery.

In one variation, a surgical simulation tray, that is insertable into alap trainer 10 for practicing surgical techniques including laparoscopicand electro-surgical methods, comprises a base, an arrangement ofanatomical organs, and a covering layer. The base comprises a rigid orsemi-rigid structure that is sized and configured to fit within or upona surgical training device 10. The base is additionally supplied withanatomical support features or receptacle portions formed by upstandingwalls that cooperate and conform in size and shape with the placement ofbody organs within the receptacle portion or upon the base. Body organs,made of elastomeric materials, are placed strategically within or uponthe base according to the specific needs of the training device and/oraccording to the target anatomy. At least one covering layer may beplaced over the entire assembly or upon specific areas thereof. Thecovering layer is sized and configured to represent one or more of theomentum, mesentery, fat, connective tissue, peritoneum, mesothelium,broad ligaments or the like. The covering layer may comprise siliconeelastomer, which is non-conductive. The non-conductive covering layer issuitable if no electrosurgical activity is used on the covering layer.If electrosurgical activity is contemplated, the covering layer iscomprised of a conductive gel such as a hydrogel. A combination ofconductive and non-conductive layers is provided when electrosurgery isdirected to one of the layers.

In addition to the organs placed within or upon the base, there may be aplurality of pathologies or defects also placed strategically relativeto the organs or within the simulated organs themselves. The pathologiesor defects may represent tumors, cysts, ectopic pregnancies or the like.For instance, a uterus may be formed having an outer layer of siliconerubber and a substantially hollow inner layer of soft polyurethane foamas described above with respect to FIG. 7. At various locations betweenthe silicone layer and the foam layer, synthetic fibroid tumors may beplaced for identification and removal by a surgical trainee. Onesimulated construction of a synthetic fibroid tumor comprises a smallquantity of very soft uncured silicone rubber. The uncured siliconerubber is mixed with a quantity of amorphous, untreated fumed silicondioxide, which acts as a filler and flow controller. The combination ofthe uncured silicone rubber and the silicon dioxide is shaped andallowed to cure. When fully cured, this combination results in anirregularly shaped, somewhat fibrous structure that resembles a humanfibroid tumor. This construction of a simulated human fibroid tumor isthen placed into a simulated organ model such as that of a uterus. Thistumor simulation is not limited for use to mimic a tumor in agynecological model, but also can be used in other organ models thatinclude tumors for practicing their removal. This tumor simulationcomprising the cured mixture of silicone rubber and silicon dioxidestrikingly resembles real-life tumors that are found in a gynecologicalsurgical situation and provides an amorphous and realistic look and feelwhen practicing surgical techniques. Dark colored dye such as red orblack may be added to the mixture before curing and mixed throughout.This construction may also be used to construct simulated ectopicpregnancies for insertion into a simulated fallopian tube of a simulatedorgan placed within the training device 10. The mixed consistency of thesilicone and filler, being very dry and shape-able, advantageouslyallows the tumors or other pathologies to be formed very creatively,easily and at any size to mimic actual physical conditions. Tumors madeof silicone and filler are non-conductive and may be fractured or tornif not properly handled.

A few examples of organ simulation models that include the combinationof conductive and non-conductive portions will now be discussed. In thesurgical procedure of a liver resection, a simulated organ model trayfor training electrosurgical procedures will have a conductive hydrogelliver, cystic duct and mesentery. These conductive portions of the modelare located adjacent to non-conductive portions of the anatomycomprising the same organ or different organs. For example, forpracticing the surgical procedure of a cholecystectomy, the organ modelincludes a cystic duct and mesothelium made from electro-conductivehydrogel and the liver and gallbladder are non-conductive. Forpracticing a sleeve gastrectomy, the simulated organ model includes oneor more of the blood vessels and the greater omentum/mesentery along thegreater curvature of the stomach made of electro-conductive hydrogelmaterial and one or more of the stomach, large intestine, and smallintestine made of non-conductive material. For practicing a gastricbypass, the simulated organ model includes one or more of the shortgastric vessels and the mesentery/omentum along the greater curvature ofthe stomach made of electro-conductive hydrogel material and the stomachmade of non-conductive material. In one variation, at least a portion ofthe jejunum and/or stomach is made of electro-conductive hydrogel. Forpracticing ovarian procedures such as the removal of fibroid tumors,treatment of ectopic pregnancy, ovarian cysts, and hysterectomy, thetraining model includes both conductive and non-conductive materials.For example, the organ model may include one or more simulated fallopiantubes, round ligament, ovarian ligament, IP ligament, broad ligament,bladder flap, uterine artery/vein, cardinal ligament, uterosacralligament, made of electro-conductive hydrogel and one or more of theuterus, ovaries, rectum, urinary bladder, ureters and kidneys arenon-conductive. In one variation, the location just above the cervixand/or just below the cervix is made of electro-conductive hydrogel forpracticing a supracervical or total colpotomy. Procedures that involvethe colon, small intestine, sigmoid or rectum may also require thatspecific portions be electrically conductive. These conductive portionsare located adjacent to non-conductive portions. For example, topractice transanal minimally invasive surgery for the local excision oftumors, the organ model would include a colon and/or rectum, and tumormade of non-conductive elastomeric material except for the areasurrounding the tumor which would be made of electro-conductive hydrogelmaterial. In another variation, at least a portion of the rectum is madeof electro-conductive hydrogel such as for the practice of transanaltotal mesorectal excision. In the practice of an appendectomy, thesimulated organ model may include one or more of themesentery/mesoappendix, appendiceal artery and blood vessels made ofelectro-conductive hydrogel and one or more of the appendix, cecum andterminal ileum made of non-conductive elastomeric material. Forpracticing a colectomy, the simulated organ model may include one ormore of the mesentery, ileocolic artery, middle colic artery, rightcolic artery, inferior mesenteric artery, inferior mesenteric vein, leftcolic artery, sigmoid arteries, rectal arteries, marginal arteries,corresponding veins, omentum, white line of Toldt, mesentericattachments to the retroperitoneum, and mesorectum made ofelectro-conductive hydrogel and one or more of the colon, liver, spleen,stomach, kidney, duodenum, retroperitoneum made of non-conductivematerial. Hydrogel material must be hydrated in order to be sufficientlyconductive and therefore it may be difficult to maintain a longshelf-life.

With reference to the covering layer, in one variation, the coveringlayer comprises a thin semi-transparent sheet of silicone rubber that iscalendared or press-formed so as to have a texture and finish thatappears to be naturally occurring. An alternate variation of thecovering layer may further comprise a thin semi-transparent sheet ofhydrogel material that is cured from slurry and allowed to developsurface features as it cures. The hydrogel material, when hydratedbecomes conductive and allows the use of electrosurgical devices. Acomposite structure for the covering layer comprises a conductive gellayer sandwiched between two silicone elastomer non-conductive layers.In such a case, one or more of the outer non-conductive layers areremoved to expose the conductive gel layer. The non-conductive siliconelayers advantageously provide a sealing for the hydrogel layer retainingthe fluid content of the conductive gel.

In another variation of the covering layer, a thin film of two-partplatinum or tin cured liquid silicone, thoroughly mixed, is placed upona sheet of textured polyethylene foam. A notched trowel or spreader isthen used to spread the silicone material over the surface of the firstlayer of foam leaving an irregular pattern of material thickness. Asecond layer of textured polyethylene foam is placed over the firstlayer of foam leaving the silicone between. A textured roller orstamping device is then moved over the surface of the second layer offoam to calendar the silicone material between the foam layers. Theresulting silicone sheet, when cured, is non-tacky and exhibits thecharacteristics of omentum, mesentery, fat etc. The sheet advantageouslyhas strong and weak regions that can be used to demonstrate the use ofmechanical dissecting instruments and scissors.

The specific organs that may be used in a surgical simulation deviceinclude a uterus 100 as shown in FIG. 13. The uterus comprises an outershell constructed of soft silicone rubber molded over a uterine form.When the shell is fully cured, it is placed over a molded foam rubberuterine form that is substantially hollow, having about a 7 to 9millimeter thick wall. Various pathologies may be placed between thesilicone shell and the foam wall. Some pathologies may be inserted intothe foam wall to mimic intramural tumors, fibroid tumors 102 or cysts.Fallopian tubes 104, ovarian ligaments 106 and other attendantstructures may be inserted into the silicone/foam structure and attachedwith adhesive. Ovarian cysts 124 may also be provided and made of thesame tumor material. Attendant structures may include the aorta 114, theinternal iliac artery 116, the ovarian artery 118, the uterine artery120, the vaginal artery 121, and the uterosacral ligament 122. Theuterine shell is the primary portion to be operated upon. In onevariation, it is constructed of silicone elastomer and thereforesuitable if the uterine model is intended to be cut or incised intraining. If electrosurgery is being practiced upon the uterine model, auterine model is selected that comprises conductive gel. Connectingstructures and tubes are constructed of silicone elastomer or conductivegel depending on the surgical modality.

Fallopian tubes 104 constructed of two-part platinum or tin curedsilicone comprising a first open end and a second open end and a throughlumen. The first open end forms a tubular structure that extends adistance of about 20 centimeters and has a diameter of about 6.5millimeters and a very thin wall of approximately 1-1.5 millimeters.Toward the end of the tubular structure, a bulbous portion is formedhaving a diameter of about 1.5 centimeters and a length of about 3centimeters. The bulbous portion transitions to a narrowing of thetubular structure to about 7 millimeters. The narrowed tubular structurethen gradually enlarges into a funnel shaped structure having a finalopen diameter of about 2 centimeters over a length of about 3.5centimeters. Before the fallopian tube 104 is removed from the form uponwhich it is made, a plurality of axial cuts 108 is made at the secondenlarged open end. When removed from the form, these cuts allow thesilicone material to move in a way that resembles human fimbria.Pathology such as an ectopic pregnancy 110 may be inserted into thebulbous portion of the fallopian tube 104 for identification orexcision. In addition, to maintain the shape of the thin walled conduitportion of the fallopian tube when folded, a length of soft fibrousyarn, such as used in knitting, may be placed within the lumen.

In the simulated uterine model, the ovaries 112 are hollow bulbousstructures formed from two-part platinum or tin cured silicone. A softpolyurethane foam support is placed within the ovarian structure. Thepolyurethane support is sized and configured to fit neatly within theovarian shell and have a nest or receptacle for pathology such as anovarian cyst 124. The trainee may cut through the ovarian wall and intothe polyurethane foam to remove the pathology and subsequently suturethe defect to close. Ovaries are made of non-conductive material and arecut with scissors or scalpel. In another variation, the ovaries are madeof conductive gel so they could be cut with electrosurgery. The cyst ismade of non-conductive material.

In another simulated organ model, a stomach comprises a hollowstomach-shaped bladder having a first open end, a second open end and anenlarged central portion. The enlarged central portion is divided by apathway that extends from near the first open end to near the secondopen end. The pathway comprises a region of silicone adhesive placedstrategically along a desired trajectory adjacent to the lessercurvature of the stomach. The opposing walls of the stomach bladder areapproximated and held together by the adhesive. The stomach may bedivided along the adhesive pathway to simulate a particular procedure.That is, the adhesive pathway directs the trainee to staple or cut alonga preferred surgical pathway. The adhesive simulates the condition inwhich several rows of staples would be placed before the cutting elementin a surgical stapler is deployed. As a result, the dissected stomachportion appears to be stapled securely and the residual stomach portionis gas tight and secure. In another variation, the adhered portion ofthe stomach is formed of conductive gel material adjacent tonon-conductive adjacent portions of the stomach. In yet anothervariation, the predetermined surgical pathway across the stomach orother organ is constructed of conductive gel material adjacent tonon-conductive material of the same organ or adjacent to non-conductivematerial of different organs and anatomical structures.

In another simulated organ model, a liver constructed of hydrogel may beplaced into the training module 10 where the procedure would involveelectrosurgical dissection. In one variation, the base or tray of thetraining module 10 receives and holds in place either a silicone liveror a hydrogel liver. A receiving feature may comprise a nest, pocket orreceptacle sized and configured to maintain in position a silicone orhydrogel or foam rubber liver depending on the needs of the particulartraining module. If a procedure required electrosurgical activity, suchas a liver resection, the liver is made of conductive gel. The base ortray is configured to accept a liver made of gel, silicone or foamdepending on the specific procedure. If the procedure to be practiceddoes not involve electrosurgery, it is far more economical to use asilicone or foam model.

While certain embodiments have been particularly shown and describedwith reference to exemplary embodiments thereof, it will be understoodby those of ordinary skill in the art that various changes in form anddetails may be made therein without departing from the spirit and scopethereof as defined by the following claims.

We claim:
 1. A surgical simulation system, comprising: a tray having abase with a perimeter and one or more anatomical receptacle portionformed by at least one upstanding wall configured to substantiallycooperate and conform in size and shape with one or more simulated bodyorgan located within the one or more receptacle portion; one or moresimulated body organ placed upon the base within the one or morereceptacle portion; and at least one covering layer placed over the oneor more simulated body organ; the covering layer being attached to theone or more simulated body organ in at least one location; wherein atleast one of the one or more simulated body organ and covering layerincludes electro-conductive gel operably severable under application ofelectrical current to simulate electrosurgery in a training environment.2. The surgical simulation system of claim 1 wherein the covering layeris attached to the tray.
 3. The surgical simulation system of claim 1wherein the system includes two or more simulated body organs and thecovering layer is placed over all of the simulated body organs locatedon the tray.
 4. The surgical simulation system of claim 1 wherein theelectro-conductive gel is located between two non-conductive areas. 5.The surgical simulation system of claim 1 wherein the electro-conductivegel defines a predetermined pathway between non-conductive regions; thepredetermined pathway being configured to simulate a pathway encounteredin real surgery for practicing electrosurgical activity.
 5. The surgicalsimulation system of claim 1 wherein the electro-conductive gel is incontact with an adjacent non-conductive area.
 6. The surgical simulationsystem of claim 1 wherein the electro-conductive gel is a layer in thecovering layer; the electro-conductive gel layer being sandwichedbetween two outer layers of elastomeric material; the two outer layersbeing not operably severably under application of electrical current forsimulating electrosurgery.
 7. The surgical simulation system of claim 6wherein the two layers of non-conductive elastomeric material areconfigured to retain moisture in the electro-conductive gel layer thatis located between them.
 8. The surgical simulation system of claim 1wherein the simulated body organs on the tray include simulated kidneys,ureters, aorta, vena cava and hepatic vessels and the covering layercovers all of the simulated body organs; the covering layer beingattached to at least a portion of the perimeter of the tray.
 9. Thesurgical simulation system of claim 1 wherein the simulated body organson the tray include a simulated transverse colon, stomach, a portion ofthe descending colon, a portion of the ascending colon, and agallbladder; and the covering layer covering all of the simulated bodyorgans.
 10. The surgical simulation system of claim 9 wherein thecovering layer is attached to the descending colon and to the liver. 11.The surgical simulation system of claim 1 wherein the covering layer isapproximately 0.010 to 0.05 inches thick.
 12. The surgical simulationsystem of claim 1 wherein the covering layer is transparent ortranslucent.
 13. The surgical simulation system of claim 1 wherein thecovering layer is made of made of elastomeric material.
 14. The surgicalsimulation system of claim 1 wherein the at least one simulated bodyorgan is made of elastomeric material.
 15. The surgical simulationsystem of claim 1 wherein the training environment is a surgicaltraining device including: a base; a top cover connected to and spacedapart from the base to define an internal cavity between the top coverand the base; the internal cavity being at least partially obstructedfrom direct observation by a practitioner; wherein the tray, simulatedbody organs and covering layer are placed inside the internal cavity.16. A surgical simulation system for the practice of electrosurgicalactivity, comprising: a simulated tissue structure comprising: an innerlayer adjacent to and in contact with an outer layer; the inner layercomprising a foam material and the outer layer comprising an elastomerichydrogel; the inner layer defines an interior cavity and both the innerlayer and the outer layer define a shape of at least a portion of auterus; and a simulated pathology located adjacent to or embedded in theinner layer; the simulated pathology being removable from the simulatedtissue structure; wherein the elastomeric hydrogel is electro-conductivesuch that it is operably severable under application of electricalcurrent to simulate electrosurgery in a training environment.
 17. Thesurgical simulation system of claim 16 further including at least onetube having a first end and a second end; the tube extending outwardlyfrom the outer layer and configured to define the shape of a fallopiantube; the tube comprising electro-conductive hydrogel material operablyseverable under application of electrical current to simulateelectrosurgery.
 18. The surgical simulation system of claim 16 whereinthe simulated pathology is made of silicone and untreated fumed silicondioxide.
 19. A method comprising the steps of: providing an organ trayhaving a base with one or more simulated body organ; a covering layerplaced over the one or more simulated body organ; the covering layerincludes a first planar layer of non-conductive material and a secondplanar layer of electro-conductive gel; the covering layer being placedover the one or more simulated body organ such that the second layer isadjacent to the one or more simulated body organ; placing the organ trayinto an internal cavity of a surgical training device such that theorgan tray is at least partially obstructed from direct visualobservation by a practitioner; the surgical training device having a topcover spaced apart from the base; the internal cavity being definedbetween the top cover and base; the surgical training device includingan aperture or penetrable simulated tissue region in the top cover;inserting a scope configured to capture video of the internal cavitythrough the aperture or penetrable simulated tissue region and into theinternal cavity of the training device; inserting at least oneinstrument through the aperture or penetrable simulated tissue regioninto the internal cavity of the training device; separating the firstlayer from the second layer with the at least one instrument.
 20. Themethod of claim 10 further wherein the step of inserting at least oneinstrument includes inserting at least one instrument configured todeliver electric current at a distal end of the instrument; furtherincluding the step of cutting the second layer with the application ofelectrical current from the instrument to simulate electrosurgicalactivity.
 21. The method of claim 19 wherein the covering layer furtherincludes a third layer of silicone material connected to the secondlayer such that the second layer is located between the first and thirdlayers.